#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/sendfile.h>

int main(int argc, char **argv)
{
    if (argc <= 3)
    {
        printf("Usage:%s ip_address port_number filename\n");
        return 1;
    }
    const char *ip = argv[1];
    int port = atoi(argv[2]);
    const char *file_name = argv[3];
    int filefd = open(file_name, O_RDONLY);
    assert(filefd > 0);
    struct stat stat_buf;
    fstat(filefd, &stat_buf);
    sockaddr_in address;
    bzero(&address, sizeof(address));
    address.sin_family = AF_INET;
    inet_pton(AF_INET, ip, &address.sin_addr);
    address.sin_port = htons(port);
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    assert(sock >= 0);
    int ret = bind(sock, (sockaddr *)&address, sizeof(address));
    assert(ret != -1);
    ret = listen(sock, 5);
    assert(ret != -1);
    sockaddr_in client;
    socklen_t client_addrlength = sizeof(client);
    int connfd = accept(sock, (sockaddr *)&client, &client_addrlength);
    if (connfd < 0)
    {
        printf("errno is: %d\n", errno);
    }
    else
    {
        sendfile(connfd, filefd, NULL, stat_buf.st_size);
        close(connfd);
    }
    close(sock);
    return 0;
}